Since the attacks on Sep. 11, 2001, the entire security infrastructure for air transport has been trained to prevent explosives, weapons or objects similar to weapons from being carried on board. Nevertheless, according to information from the pilot's union. Cockpit, the luggage problem has become even worse. There is said to be an actual trend toward business travelers transporting hazardous goods. This is because, on the one hand, there are scientists who fly to a congress with toxicological samples in their luggage, and on the other hand there are marketing people who travel to an exhibition with 400 gas lighters, or fitters and installation specialists who are traveling with hazardous special tools to carry out repairs for customers. Two particularly serious aircraft accidents have already been caused by hazardous goods on board. The crash by a DC-9 belonging to the US budget airline ValuJet in May 1996 (110 deaths) and the fire on a pilgrim flight in a Lockheed TriStar in Saudi Arabia in 1980 (301 deaths). In the opinion of specialists, accidents such as these can occur again at any time, particularly in the case of so-called Hadj pilgrim flights during which, as before, it is standard practice to carry gas ovens on board as hand luggage.
The primary interest with regard to on-board luggage is to detect weapons or objects similar to weapons, as well as substances and items which represent a potential hazard when used by a passenger. In the case of the luggage that is carried in the aircraft fuselage, the primary factor is to detect explosives which, for example, could be detonated by time fuzes or remote fuzing. It is also important to identify the devices required to detonate the explosive materials. Widely differing methods for identification of such substances have already been introduced, such as X-ray installations, tomographs, etc. for automatic or semi-automatic checking. Particularly at relatively large airports, the normal practice in this case is to first of all automatically check all luggage items. Luggage items which are classified as being critical in this first check are than subjected to further checks which can then, for example, also include a manual check by security personnel opening the luggage item.
If it is found that a luggage item contains explosive material, this luggage item is isolated and, for example, is taken to explosive chambers or explosive containers, and is deliberately destroyed.
Apparatuses or methods which contribute to the precautions against such hazards have been known for a very long time for the patent literature.
By way of example, DE 101 25 531 A1 discloses an inspection installation for inspection of objects, in particular for identification of impermissible objects in travel luggage items, having beam sources with detector rows aligned with them, which are arranged around a transport shaft, in which the beam sources produce at least three beams which are applied to the object from at least three beam levels.
In this case, it is considered to be novel and inventive that the inspection installation is included in a housing of a separate device, or vice versa, and that, in order to lengthen a beam tunnel, the inspection installation has a shield, which interacts with the transport shaft, before the transport shaft, or is fitted around an installation part which belongs to the separate device (claim 1).
In the case of this installation, only in this specific case is there an aim to reduce the space requirement and therefore to obtain an improved capability for retrofitting.
In the case of the method known from DE 101 39 672 A1, the aim is to specify improved checking for the inspection of an object, in particular of a luggage item, in which beams are emitted from a fixed-position beam source, the object is transported in a straight line through the beams and, in the process, the intensity of the beams which have not been absorbed is detected by a detector arrangement and is processed to form an image of the object, this is achieved in that, after passing through the beams that are used, the object is rotated by a rotation device through an angle in order to change its transport position, is once again transported through the beams, and a further image is produced in this case (claim 1).
The magnitude and/or the direction of the rotation angle are/is in this case entered manually by an operator.
The respective luggage item is in this case moved by means of a transport device which provides straight-line conveyance. No high-speed transport capability, bypassing the normal conveyor belts, is possible in this case.
Furthermore, for relatively new developments in the security sector, DE 11 2004 002 474 T5 discloses a method for detection of small amounts of specific nuclear materials which are transported impermissibly in cargo. Substances such as these may, for example, be used to produced improvised nuclear devices (INDs). Very-high-priority research programs are currently being carried out in order to counter such hazards, initiated by the US Dept. of Homeland Security, DHS. In general, this does not address the transport of high-risk luggage.
In addition, for example, DE 11 2004 002 474 T5 describes the already developed security screening methods and apparatuses in the prior art, taking account of the latest developments and potential hazards identified so far.
Specifically in this context DE 11 2004 002 474 T5 cites passive radiation monitoring systems and single-energy radiography systems, as well as dual-energy radiography (DER) systems.
The method disclosed here is based on the object of allowing a screening method for effective prevention of impermissible transport of SNMs (specific nuclear materials) at the critical entry and exit monitoring points by the detection of even small amounts of SNMs in freight items.
The method described here consists in carrying out multi-view-multi-energy radiography by irradiation of an object with a plurality of discrete high-energy gamma beams, based on nuclear reactions, in a plurality of different orientations, detection and recording of the radiation which passes through the object, by means of at least one detector arrangement.
Furthermore, the method described here consists in the indication of the presence of a high-Z substance by detection of a difference in a transmission-attenuation characteristic of the high-Z substance in contrast to low-Z and medium-Z substances (claim 1).
It is evident from the described prior art that technology for detection of hazardous substances must continuously be adapted to new potential hazards.
This requires the use of novel detection methods and new development of appropriate monitoring stations. However, since newly developed monitoring stations must be associated with the existing monitoring capabilities and must be included in the luggage transport process and luggage handling process, it is necessary to create faster and more effective transport and distribution capabilities for the recording and passing on of luggage which has already been identified during the initial check as being conspicuous.